0000000000053062
AUTHOR
R. Cortimiglia
Effect of claustrum stimulation on neurons of the contralateral medial oculomotor area, in the cat
In chloralose-anaesthetized cats, the extracellular spontaneous unitary activity was recorded from 157 neurons, located in the medial oculomotor area. 98 units were identified as projecting onto the superior colliculus. Electrical stimulations of the contralateral claustrum provoked, on 13 of these cells, an excitatory effect, lasting 10-35 ms and appearing with a latency of 20-50 ms. Full length section of the corpus callosum totally abolished the contralateral claustrum effect. The results suggest that in the cat, the claustrum may have a role in the bilateral control of the visuo-motor performance.
The action of iontophoretically applied acetylcholine and dopamine on single claustrum neurones in the cat.
Abstract The effects of iontophoretically applied acetyl-choline (ACh) and dopamine (DA) on spontaneously active claustral neurones, in chloralose-anaesthetised cats, have been investigated. Acetylcholine had both facilitatory and inhibitory effects in almost the same proportions. The action of DA was prevalently inhibitory. Two types of inhibitory response to ACh and DA are described: short-lasting inhibition and long-lasting inhibition. The excitatory response always outlasted the period of drug application.
Unit study in cat claustrum of the effects of iontophoretic neurotransmitters and correlations with the effects of activation of some afferent pathways
Glutamate (Glut), acetylcholine (ACh) and dopamine (DA) were iontophoretically applied on cat claustral neurons. Glut did not affect all the neurons; ACh had both excitatory and inhibitory effects, while DA was prevalently inhibitory. An analysis was made of the time-course of excitatory and inhibitory responses on the basis of the mean firing rate variations during and after ACh and DA release. Three types of responses are described for each drug: short lasting inhibition, long lasting inhibition and long lasting excitation. The experimental data were statistically elaborated. The effects of ACh and of DA were compared with those of activation obtained by sensorial peripheric and thalamic …
Effects of iontophoretic 5-hydroxytryptamine on the unitary discharge frequency of caudate nucleus neurons in the rat
AbstractSummaryMicroiontophoretic application of 5-hydroxytryptamine (5-HT) on rat caudate nucleus neurons has both facilitatory and inhibitory effects on the discharge frequency of the neurons; in many cases 5-HT has a two-phase action. An analysis was made of the behaviour of facilitatory and inhibitory responses in time considering the mean firing rate variations during and after 5-HT iontophoretic release. Six types of responses have been described : A : short lasting excitation, B : long lasting excitation, C : short lasting inhibition, D : delayed-onset inhibition, E : inhibition followed by excitation, F : excitation followed by inhibition. Also no topographic localization could be m…
The role of the claustrum in the bilateral control of frontal oculomotor neurons in the cat.
The effect of claustrum (CL) stimulation on the spontaneous unitary activity of ipsi and contralateral frontal oculomotor neurons, was studied in chloralose-anaesthetized cats. A total of 205 units was bilaterally recorded in the medial oculomotor area, homologous of the primate "frontal eye fields"; 127 neurons were identified as projecting to the superior colliculus; for 33 of these last units stimulation of the ipsilateral CL provoked an excitatory effect lasting 10-25 ms and appearing with a latency of 5-15 ms; on 8 units the excitatory effect was followed by an inhibition lasting 100-250 ms. Ninety-eight of the 127 neurons were also tested through activation of the contralateral CL: 13…